Why not tackle the actual problem? Having to run each individual round through a Lee FC Die on a single stage seems to eliminate the benefit of using a progressive in the first place.
What kind of sizing die are you using? Can you screw it down further? What kind of gun?
Whatever the answer this should not be happening. I would think it would have more to do with crimping, and not getting the bell out of the case.
Any resizing die should do exactly that. If you are having an intermittent problem something is not making sense.
Some people talk of Glocked Brass, but I have never had an issue with my G17, and I believe the issue is more to do with 40, but I am not sure.
Doesn't sound like you are new to reloading, are you?